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<h2 style="font: normal normal bold medium verdana;color:#191970;">UK  DATA  ARCHIVE:  IMPORTANT  STUDY  INFORMATION</h2>
<div align="justify">
<h3 style="font: normal normal bold small verdana;color:#191970;margin-top:10;margin-bottom:10">Study Number 5494 - British Election Study, 2005: Face-to-face Survey</h3>

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<h3 style="font: normal normal bold small verdana;color:#191970;margin-top:10;margin-bottom:10">DATA PROCESSING NOTES</h3>
<br />
<b>Data Archive Processing Standards</b>

<p/>The data were processed to the UK Data Archive's A* standard. This is the 
Archive's highest standard, and means that an extremely rigorous and 
comprehensive series of checks was carried out to ensure the quality of the data 
and documentation.Firstly, checks were made that the number of cases and 
variables matched the depositor's records. Secondly, checks were made that all 
variables had comprehensible variable labels and all nominal (categorical) 
variables had comprehensible value labels. Where possible, either with reference 
to the documentation and/or in communication with the depositor, labels were 
accordingly edited or created. Thirdly, logical checks were performed to ensure 
that nominal (categorical) variables had values within the range defined (either 
by value labels or in the depositor's documentation). Lastly, any data or 
documentation that breached confidentiality rules were altered or suppressed to 
preserve anonymity. 

<p/>All notable and/or outstanding problems discovered are detailed under the 'Data 
and documentation problems' heading below. 








<br /><br /><b>Data and documentation problems</b>
<p/>No problems left unresolved.



<br /><br /><b>Data conversion information</b>


<p/>From January 2003 onwards, almost all data conversions have been performed 
using software developed by the UKDA. This enables standardisation of the 
conversion methods and ensures optimal data quality. In addition to its own data 
processing/conversion code, this software uses the SPSS and Stat/Transfer 
command processors to perform certain format translations. Although data 
conversion is automated, all data files are also subject to visual inspection by 
a UKDA data processing officer.
<p/>With some format conversions data, and more especially internal metadata (i.e. 
variable labels, value labels, missing value definitions, data type 
information), will inevitably be lost or truncated owing to the differential 
limits of the proprietary formats.A UKDA Data Dictionary file (in rich text 
format), corresponding to each data file, is usually provided for viewing and 
searching the internal metadata as it existed in the originating format. These 
files are called:

[data file name]_UKDA_Data_Dictionary.rtf

<br /><br /><b>Important information about the data format supplied</b>

<p/>The links below provide important information about the format in which you have 
	been supplied the data. Some of this information is specific to the <i>ingest 
	format</i> of the data, that is the format in which the UKDA was supplied the 
	data in. The ingest format for this study was
SPSS
<br /><br />
Please click below to find out information about the <em>format that you have 
been supplied the data in</em>.
<br /><br />
<p/><a href="javascript:toggleDiv(document.getElementById('SPSS'))">SPSS (*.por)</a>
<div id="SPSS" style="CURSOR: hand;display:none">
	<p/><b>SPSS portable (*.por files)</b>
	<br />If SPSS portable was not the ingest format, this format will generally either 
		have been created via the SPSS command processor (e.g. if the ingest format is 
		SPSS .sav, SAS, Excel, or dBase), or if the ingest format was STATA, the SPSS 
		version will be created via the Stat/Transfer command processor. If the ingest 
		format was undelimited text, the data will have been read into SPSS using an 
		SPSS command file. 
	<p/>Issues: There is very seldom any loss of data or internal metadata when 
		importing data files into SPSS. Any problems will have been listed above in the 
		Data and Documentation Problems section of this file.<p/>
</div>

<a href="javascript:toggleDiv(document.getElementById('STATA'))">STATA (*.dta)</a>
<div id="STATA" style="CURSOR: hand;display:none">
	<p/><b>STATA (*.dta files)</b>
	<br />If STATA was not the ingest format, all STATA files will have been created from 
		SPSS .sav format via the Stat/Transfer command processor. Importantly, 
		Stat/Transfer's optimisation routine is run so that variables with SPSS write 
		formats narrower than the data (e.g. numeric variables with 10 decimal places of 
		data formatted to FX.2) are not rounded upon conversion to STATA because they 
		are converted to 'doubles ' rather than floats. User missing values are copied 
		across into STATA (as opposed to being collapsed into a single system missing 
		code).
	<p/>Issues: There are a number of data and metadata handling mismatches between SPSS 
		and STATA. Where any data or internal metadata has been lost or truncated, this 
		will have been automatically logged in this file:
	5494_SPSS_to_STATA_conversion.rtf
		Note that the complete internal metadata has been suppliedin the UKDA Data 
		Dictionary file(s): [data file name]_UKDA_Data_Dictionary.rtf
</div>

<br /><a href="javascript:toggleDiv(document.getElementById('Tab'))">Tab-delimited text (*.tab)</a>
<div id="Tab" style="CURSOR: hand;display:none">
	<br />If tab-delimited text was not the ingest format, tab-delimited fileswill have 
		beencreated from SPSS portable files via the SPSS command processor, and also 
		from Excel and MS Access files. When exporting from Access data tables to 
		tab-delimited text, thepotentially problematicspecial characters (tabs, 
		carriage returns, line feeds, etc.) allowed by Access memo and text fields are 
		stripped out by the UKDA. 

	<p/>Issues: Date formats in SPSS are always exported to mm/dd/yyyy in tab-delimited 
		text format - sothere be be amismatch with the documentation on such 
		variables. Variables that include both date and time such as dd-mm-yyyy hh:mm:ss 
		(e.g. 18-JUN-2001 13:28:00), will lose the time information and become 
		mm/dd/yyyy. If the time information is critical, a new variable will have been 
		created in the tab-delimited data file by the UKDA. All users of the data in 
		tab-delimited format should consult the UKDA Data Dictionary file(s):  [data file name]_UKDA_Data_Dictionary.rtf

	<p/>If the data was exported from MS Access, more limited 'data documenter' 
		information is suppiedin the file(s): [data table name]_variableinformation.rtf
		These files may also contain SQL setup information.
</div>


<br /><a href="javascript:toggleDiv(document.getElementById('Excel'))">MS Excel (*.xls files)</a>
<div id="Excel" style="CURSOR: hand;display:none">
	<br />If MS Excel was not the ingest format, Excel fileswill havebeencreated via 
		the SPSS command processor. The date and time issues noted under tab-delimited 
		formatapply to SPSS to Excel conversion via the SPSS command processor. 
</div>

<br /><a href="javascript:toggleDiv(document.getElementById('SAS'))">SAS (supplied as *.dat and *.sas)</a>
<div id="SAS" style="CURSOR: hand;display:none">
	<p/>If SAS was not the ingest format, all SAS files will have been created from SPSS 
		.sav format via the Stat/Transfer command processor. The data files are provided 
		as a fixed-width text file (*.dat) and a SAS command file (*.sas), which when 
		run will create a SAS dataset. This enables the user to recreate the SAS dataset 
		and formats library in almost all versions of SAS and all operating systems.

	<p/>Issues: The main loss of information when converting from SPSS to SAS is 
		user-missing value definitions. By editing the .sas file, the user can choose 
		whether to collapse all user-missing values into system missing or preserve 
		thevalue and lose the user-missing definition. To achieve the latterthe 
		following section of the .sas file should be removed before running it: 

	<p/>/* User Missing Value Specifications */

	<p/>Note that the complete internal metadata has been suppliedin the UKDA Data 
		Dictionary file(s): [data file name]_UKDA_Data_Dictionary.rtf
</div>

<br /><a href="javascript:toggleDiv(document.getElementById('Access'))">MS Access (*.mdb files)</a>
<div id="Access" style="CURSOR: hand;display:none">
	<p/>Due to the substantial incompatibilities between versions of MS Access, the UKDA 
		only make data available in MS Access format if this is the ingest format and 
		the database contains important information in addition to the data tables 
		(coding information, forms, queries, etc.).
</div>


<br /><br /><b>Conversion of documentation formats</b> 
<p/>Electronic and paper documentation supplied with this study is usually 
	incorporated into the UKDA User Guide (in PDF format). The conversion programmes 
	used are the latest versions of Adobe PDF Writer for electronic documentation 
	and Adobe Paper Capture (Acrobat 'plugin' version) for paper documentation. 
	Occasionally, someof the electronic documentation cannot be usefully converted 
	to PDF (e.g. MS Excel files with wide worksheets) and this is supplied ina more 
	appropriate format. All User Guides are fully bookmarked.
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